president obama and the first lady left for south africa, board air force 1 joined by george bush and his wife. are ali velshi is leading our team in johannesburg. ali, set the scene for us literally hours before the event tomorrow in johannesburg. >> well it's gone cold, tony, it's raining tonight in johannesburg. it was a clear day. police were setting up barricades and rerouting. you could see dignitaries coming in and police convoys. as you said jimmy carter is here as well. george w. bush, bill clinton will be here, world leaders from all over the place. i had a chance to sit down with jimmy carter, who knew nelson mandela very well. he was on the same plane coming down. he said in all the times he knew nelson mandela, he never said thank you to the u.s. government to end apartheid. here's why. >> i would say i had many talks with nelson mandela. i never heard him say, that he was grateful to the united states. he was grateful to cuba, he was grateful to others that spoke up for him while he was still in prison. he was grateful to the people that condemned the apartheid regime. b